diff --git a/moo/mod/ffi.c b/moo/mod/ffi.c
index 401c53a..98558ec 100644
--- a/moo/mod/ffi.c
+++ b/moo/mod/ffi.c
@@ -113,7 +113,7 @@ static moo_pfrc_t pf_open (moo_t* moo, moo_mod_t* mod, moo_ooi_t nargs)
 	dc = dcNewCallVM (4096); /* TODO: right size?  */
 	if (!dc) 
 	{
-		moo_seterrnum (moo, moo_syserr_to_errnum(errno));
+		moo_seterrwithsyserr (moo, 0, errno);
 		moo->vmprim.dl_close (moo, handle);
 		goto softfail;
 	}